Is there a duty to report another lawyer's use of fake, AI generated citations?

 As I am sure you know, Model Rule 8.3(a), which has been adopted in some form or another in every state, holds that "[a] lawyer who knows that another lawyer has committed a violation of the Rules of Professional Conduct that raises a substantial question as to that lawyer's honesty, trustworthiness or fitness as a lawyer in other respects, shall inform the appropriate professional authority."

So what happens when a lawyer notices that their opponent's court documents contain fake-"halucinated"-AI generated quotes or citations?  Does the lawyer have a duty to report it to the disciplinary authorities?  Evidently, it would be tactically wise to report it to the court in the litigation, and to use it against the opposition in argument, but the issue is not whether to report it to the court, the issue is whether to report it to the disciplinary authorities.

To my knowledge this question has not been addressed but a strict reading of the text of the rule suggests there is a duty to report, and a recent case in California might provide some support for that conclusion.

As reported in LawSites, 

A new decision from the California Court of Appeals adds an intriguing dimension to the growing body of AI hallucination sanctions cases, raising the question of a lawyer’s duty to detect fabricated, AI-generated citations — not in the lawyer’s own filings, but in an opponent’s.

While the court did impose a $10,000 sanction on the attorney who filed two appellate briefs containing fake citations, it also declined to award attorneys’ fees or costs to the opposing counsel, because of counsel’s failure to report the fake citations to the court or even to detect them.

That makes this what may be the first judicial decision to touch on on whether lawyers have a duty to detect and report their opponents’ AI-generated fake citations.

Of course, Rule 8.3 is based on "knowledge" and a lawyer could say that they did not know the opponents cases were fake, but then it could be argued that admitting to that is admitting to violating the duty of competence or diligence.  

So, it is possible that not only there is a duty to report, but that there is a duty to investigate and determine the validity of the opponent's sources in order to determine if the duty to report applies.